Method for braking aircraft and turbo fan jet engine for implementing the method

The method involves discharging a part of a secondary air stream to reduce residual thrust of a turbofan (1). The air stream is discharged using a radial opening unit of an engine nacelle (9). The opening unit has an orifice (12) that is closed or opened by a door (13). The air stream passes in a secondary tube (10) defined between a case (8) of a turbofan core and an inner wall of the nacelle. An independent claim is also included for a turbofan.